These boxes are intended for use at ultra low temperatures. Constructed from polycarbonate, they can withstand storage at -196°C to +121°C and are suitable for immersion in liquid nitrogen. The grid index located on the rack itself, instead of on the lid enables quick and efficient sample location without any confusion due to lid placement. Boxes also feature vents and holes in both base and lid for rapid draining and complete avoidance of a pressure differential.